Solution Strengthened Ductile Iron SSDI

Dura-Bar SSDI is a grade of ductile iron that combines the elevated mechanical strengths of a pearlitic ductile iron with the machinability advantages of a ferritic ductile iron. By combining the best of both desired properties, Dura-Bar SSDI is an attractive grade of ductile iron that provides several benefits towards designing and manufacturing of metal components. Download the SSDI Product Brief or the SSDI Sales Flyer to learn more.

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Dura-Bar Solution Strengthened Ductile Iron SSDI

Typical Applications

Fluid Power:

Compressors Rotors, Hydraulic Manifolds & Cylinders.

Oil & Gas:

Plug Value Inserts and Crossheads

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Heat Treat Response

Initial test results prove Dura-Bar SSDI can be oil quench hardened from 1650° F (898° C) to a hardness Rockwell C 35–40. From these tests, it can be concluded that there is an overall uniformity and consistency. When untreated, SSDI’s microstructure is primarily ferritic, however when heat treated, the microstructure changes and becomes martensitic.


The microstructure consists of Types I & II nodular graphite. Microstructure attributes can be summarized as 85% nodularity. Pearlite percentage for the center and edge of the bar is 5–30% and 0–15%, respectively.

Microstructure area diagram

Center Area

100x, etched in 5% Nital

Solution strengthened ductile iron microstructure at center

Edge Area

100x, etched in 5% Nital

Solution strengthened ductile iron microstructure at edge


Dura-Bar Ductile Iron SSDI is a non-stock grade, which can be ordered in volume quantities from our distributors.

Technical Specifications

Chemical Composition

*Carbon and silicon targets are specified for each bar size in order to maintain mechanical properties. Magnesium is added as an inoculant to produce nodular graphite.

Sulfur0.025% Max
Phosphorus0.05% Max

Mechanical Properties

Hardness properties for various diameters are shown in the table. Hardness properties listed are minimum and maximum across the bar. For rectangles, squares and shapes, the hardness properties will depend on minimum and maximum section thickness and will be supplied on request.

Size RangeBHN

Tensile strength is determined from a longitudinal test specimen take from mid-radius of the as-cast bar.

Mechanical Properties
Tensile strength psi (min)75,000
Yield strength psi (min)55,000
Elongation (min)15%